# Why Newtons?

#### MarkII

##### Well-Known Member
Which is why I am not an engineer or an architect. :roll:

I color outside of the lines.

MarkII

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#### MarkII

##### Well-Known Member
I have to disagree with that - there are industry standards. American industry recognizes SAE fractions, and often decimal inches and Metric, but the scale you gave it not typically used.
SAE (I had to look that one up) sets standards for the automotive, commercial vehicle and aerospace industries. Outside of those areas, how are their standards applicable? If I want to build a house (or design a model rocket), will I be required to use the same standard measurements that motor oil and auto parts use? A board or a piece of drywall or a body tube may come in a certain standard length, but I can cut it to any length that I want, right? From what I can tell, "SAE measurements" means "non-metric." Is there a table of standard fractions that is used across all disciplines?

What are the inside diameters of either BT-60 or BT-70, stated in fractions?

I can understand the need for standardization for such things as nuts and bolts (and the tools that drive them), but if I submit a blueprint that includes an interior wall length of say, 8 feet, 2-2/3 inches, what is the problem?

MarkII

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#### luke strawwalker

##### Well-Known Member
BTW, one of the earliest proponents of the metric system, who advocated for it for many years prior to its formal creation, was an American, Benjamin Franklin. Metrification is as American as baseball, apple pie, the Liberty Bell and Super Bowl Sunday.

MarkII

Baseball originated from cricket, a British game...

Apples originated in China and spread to Europe before being brought to America...

The Liberty Bell was cast by men born British by birth, according to European bellmaking standards...

Super Bowl Sunday... you're on your own on that one...

:roll::roll::roll:

There's an argument for and against ANYTHING... LOL OL JR

##### Well-Known Member
Rounders is a game played between two teams each alternating between batting and fielding. The game originates in England and has been played there since Tudor times, with the earliest reference being in 1745 in A Little Pretty Pocket-Book where it is called "baseball".

The Liberty Bell was cast by the Whitechapel Bell Foundry in London.

English apple pie recipes go back to the time of Chaucer. And this recipe even includes figs.

#### MarkII

##### Well-Known Member
If I specified in my blueprints that I would need roof beams that were 127mm x 127mm by 762cm long, do you think my contractor in Ypsilanti would have a problem with that?

MarkII

##### Well-Known Member
SAE (I had to look that one up) sets standards for the automotive, commercial vehicle and aerospace industries. Outside of those areas, how are their standards applicable? If I want to build a house (or design a model rocket), will I be required to use the same standard measurements that motor oil and auto parts use? A board or a piece of drywall or a body tube may come in a certain standard length, but I can cut it to any length that I want, right? From what I can tell, "SAE measurements" means "non-metric." Is there a table of standard fractions that is used across all disciplines?

Well there is this one , base on SAE standards
https://www.seoconsultants.com/charts/inches-decimal/print.asp

What are the inside diameters of either BT-60 or BT-70, stated in fractions?

I can understand the need for standardization for such things as nuts and bolts (and the tools that drive them), but if I submit a blueprint that includes an interior wall length of say, 8 feet, 2-2/3 inches, what is the problem?

MarkII

The problem is no carpenter or drywall installer carries a tape measure with 1/3" on it! They carry a standard american measure,which is based on SAE fractions, probably graduated in 1/32". So your 2/3" would be translated as 21/32" which is within a tolerance of 1/32"

Edit: when I worked at Armstrong World Inds we would get oversees orders for ceiling panels 600mm x 600mm. We cut them at 23 5/8" - close but not exact. Why? - this billion dollar, multi national company would not buy metric tape measures just for a few special orders.

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#### MarkII

##### Well-Known Member
Rounders is a game played between two teams each alternating between batting and fielding. The game originates in England and has been played there since Tudor times, with the earliest reference being in 1745 in A Little Pretty Pocket-Book where it is called "baseball".

The Liberty Bell was cast by the Whitechapel Bell Foundry in London.

English apple pie recipes go back to the time of Chaucer. And this recipe even includes figs.
So no American customs and cultures are truly native-grown, then. They all are all derived from Old World antecedents, right?

MarkII

#### luke strawwalker

##### Well-Known Member
Andrew... I hope you see why there are some questions that should NEVER be asked... LOL

There are no stupid questions, just stupid answers... but there ARE some questions that should never be asked...

Don't ask, don't tell... it's not just a good idea, it's the LAW!!! LOL :dark:

:roll: Later! OL JR

#### MarkII

##### Well-Known Member
Those are fractions that are based on powers of 8. This is customary here, but it isn't the only way to skin a cat.

The problem is no carpenter or drywall installer carries a tape measure with 1/3" on it! They carry a standard american measure,which is based on SAE fractions, probably graduated in 1/32". So your 2/3" would be translated as 21/32" which is within a tolerance of 1/32"
But he could obtain such a rule if he wanted to, and if it was absolutely required by the job. They are available.

Now what if I said that I needed boards that were eight and two-thirds feet long?

MarkII

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##### Well-Known Member
But he could obtain such a rule if he wanted to, and if it was absolutely required by the job. They are available.

See the edit to my previous post - unless it's a million dollar order they will use what they have - if they have to buy a new measure just for you they will charge you for it.(I'm serious on that one)

Now what if I said that I needed boards that were eight and two-thirds feet long?

MarkII

ABSOLUTELY NOT! You will take 104" 'cuz that's what my tape measure says and you will be happy with it!

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#### MarkII

##### Well-Known Member
See the edit to my previous post - unless it's a million dollar order they will use what they have - if they have to buy a new measure just for you they will charge you for it.(I'm serious on that one)

ABSOLUTELY NOT! You will take 120" 'cuz that's what my tape measure says and you will be happy with it!
Hence the problem of converting fractions of an inch (powers of 8), fractions of a foot (powers of 12) and fractions of a yard (powers of 3). You would be 16 inches off. Eight and two-thirds feet is 104 inches, not 120 inches.

But converting millimeters to centimeters, centimeters to meters and meters to kilometers is so much harder.

MarkII

##### Well-Known Member
Hence the problem of converting fractions of an inch (powers of 8), fractions of a foot (powers of 12) and fractions of a yard (powers of 3). You would be 16 inches off. Eight and two-thirds feet is 104 inches, not 120 inches.

But converting millimeters to centimeters, centimeters to meters and meters to kilometers is so much harder.

MarkII

Yeh you're right I was in a hurry and thinking 2/3 of a yard - which is why you don't use thirds in construction, it's too confusing!

#### MarkII

##### Well-Known Member
BTW, guys, I'm just having a little fun here playing devil's advocate. In fact, I readily acknowledge the truth of what Dale, strawwalker, Adrian, JAL, Bob and Micro have said, even though I have been arguing against you. ("Devil's advocate?" my wife says. "More like playing the fool." She says that I seem to have made a real career out of that last bit. She might be right.)

I buy nearly all of my hardware in fractional (SAE? Imperial? English?) sizes, since it is the standard here. All hardware stores sell metric-sized hardware, too, and I occasionally get it if it fits my needs better. I do nearly all of my measuring in fractional units as well, even though I have a variety of scales to choose from. Habit, I guess; it's what I grew up with, and so as I mentioned awhile back, it is how I see the world. But I am well acquainted with most basic SI units, too.

Even though it is really frowned on, I sometimes mix units. What can I say, I don't always follow the rules (pun not entirely intended). Sometimes the best, most accurate measurement that I can get is in inches PLUS millimeters. An example is my 1/6 scale Sandia Sandhawk project. The fins of the Sandhawk, when scaled to 1/6, have a root edge thickness of 0.17" and a tip edge thickness of 0.086". Since I want to build them out of solid wood (for strength), I am limited here in the US to wood sheets that are provided in fractional thicknesses, the thinnest being 1/64". Creating the root edge thickness is pretty easy: 11/64" is close enough to 0.17' for my purposes. The tip edge (0.086") is the bear, though. There is no easy way to represent that dimension in either millimeters or in fractions of an inch (based on 8). But it turns out that if I use a mix of both systems, I can get pretty close.

Adding 3/64 of an inch, plus 1 mm pretty much nails it. So to construct the fins, I take three pieces of 1/64" aircraft plywood; one each for the two sides of the fin and the third for core. Then I take two pieces of 1/16" thick aircraft plywood and sandwich each one between a side piece and the core.

This gives me my root edge thickness: 0.015625 + 0.0625 + 0.015625 + 0.0625 + 0.015625 = 0.171875. The real Sandhawk's fins tapered in thickness from the root edge out to the tip; they also had a knife-edge bevel along the leading edge, but I'm dealing with that in a different way. To get that tapering thickness, I sanded a slope in each of the 1/16" thick inserts on one side from their full thickness at the root edge to a thickness of 0.5 mm at their tip edges. The resulting edge is made up of layers of: 0.015625" + 0.5 mm + 0.015625" + 0.5 mm + 0.015625" = 0.086245" which is close enough!

If I could have made the tip edge exactly half the thickness of the root edge, or 11/128", it would have been even closer. But where would I have found wood that was 1/128" (0.0078125") thick? I was really stuck on this until I realized one day that I could achieve the right thickness by mixing units.

MarkII

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#### Larry Curcio

##### Well-Known Member
If I specified in my blueprints that I would need roof beams that were 127mm x 127mm by 762cm long, do you think my contractor in Ypsilanti would have a problem with that?

MarkII

OOC, what are the measurements of your famous water tower?

#### MarkII

##### Well-Known Member
OOC, what are the measurements of your famous water tower?
I'm not in Ypsilanti; I just used that as an example of an American city. But according to Wikipedia, the Ypsilanti Water Tower is 147 feet tall and 85 feet in diameter at its base. The tower is listed in the National Register of Historic Places. I lived in Michigan until I was 16 (and my sister attended EMU), but I cannot recall ever seeing the tower.

By the way, the dimensions of the roof beams that I mentioned (127 mm x 127 mm x 762 cm long) could also be expressed as exactly 5 inches x 5 inches x 25 feet long.

MarkII

#### luke strawwalker

##### Well-Known Member
No worries Mark... this is the sort of thing that gets everybody's blood pressure up and nobody can agree on and the argument is ultimately meaningless because NOBODY is going to convince ANYBODY to change their mind-- sorta like religeon and politics...

What really wrankles me is metric fasteners... That I REALLY wish would either become all metric or all SAE... and personally I prefer SAE because the bolts are stronger for a given size, or at least seem to be. It never fails that I start working on a vehicle around here and end up needing both metric AND SAE tools to finish the job-- sometimes two different fasteners in the same component-- one metric one SAE! EXTREMELY IRRITATING!!!

Most of the farm stuff is SAE. Most engine, interior, and body fasteners on the trucks are metric; the frame and some transmission/rear end/brake hardware is usually SAE, and the suspension stuff is mostly SAE with some metric thrown in here and there. Infuriating! I usually just grab my metric crescent wrench for the ones that are easy to get to... :roll:

The WORST thing is metric hydraulic fittings... they were a big deal a decade or so ago, now they're almost impossible to find, even at dedicated hydraulic shops! Apparently, most of the forien manufacturers, at least on units sold in North America, seem to have gone to SAE hydraulic fittings on all their equipment. I have a German-built CLAAS grain combine manufactured at the factory in Horstfeld (IIRC) that was imported into the US under a deal with Ford in the early 70's-- there was a loophole in the import laws that machinery could be shipped to the US without an engine, have a US engine installed in it, and not have to pay import duties, as the 'incomplete' machine was considered "parts". So Claas sent a bunch of combines to the US in a deal with Ford, who installed 300 cubic inch (4.9 liter) inline-six engines typically used in pickups in the combines, then painted the lime green combines blue and white, stuck FORD vinyl decals on them and sold them at Ford tractor dealers. We got one "cheap" and have run it for 30 years, but the hydraulic hoses have become old and brittle and I had one break, and when I went to get a replacement made, found out that the thing is metric and I can't get any-- after visiting EVERY hydraulic house in the Houston area that I could find. The metric fittings just aren't around anymore. What's worse, the hose was NOT the typical steel-mesh wire-reinforced hydraulic hose typically used, but a FIBERGLASS STRAND reinforced hose, which is VERY brittle and weak compared to steel... I managed to find a shop that could splice the hose back together, but if it ever breaks again... (or any of the other 30 hoses on the machine for that matter... )

Then there's metric driveshafts... most farm equipment up until about 10-15 years ago had SAE drivelines, yokes, slip joints, and U-joints. No more-- now they're all Weasler Metric... and the metric U-joints and lemon-shaped tubes are MUCH weaker than the equivalent sized SAE shafts using square shafting for slip joints and thicker yokes, and beefier U-joints. But what can you do... SAE drivelines are getting to be a niche market for older equipment, and unavailable for the sizes currently used on most newer equipment. My Holland built PZ Zweegers hay mower uses a Weasler driveshaft and I just broke another one a couple weeks ago... Another \$200 bucks down the drain... :confused2:

OH well... it WOULD really make most mechanic's happy (and farmers) if they'd standardize some of this kind of stuff and get off the fence, one way or the other... I know what a boon it's been having common trouble codes and stuff in the vehicle computers-- unlike the 'every car is different' crap of the late 80's/early 90's when I was in mechanic's school...

Later! OL JR

#### MarkII

##### Well-Known Member
I didn't view our exchanges over the last 24 hours as an argument but rather as a bull session. Setting off an argument was not the purpose at all, and I hope that no one took it that way. Nothing was at stake; just throwing up ideas and seeing if they would fly. An old friend back in college once described this as "shooting from the lip." Thanks to everyone who participated in the exchange; it was stimulating and fun for me, and I hope it was for everyone else, too.

MarkII

#### MarkII

##### Well-Known Member
LS: After reading your last post, I really wish I knew more about farm machinery and technology. But for the hydraulic lines, there isn't a hose in an SAE size that is equivalent or even close to the size of the original that could be adapted or made to work?

Don't laugh, but more than once I have had a metric crescent wrench fit over a nut better than the wrench in the fractional size that the nut is supposed to be. But the reverse never seems to occur (fractional-sized wrenches fitting metric nuts). Now, more often than not, when I have a nut to loosen or a bolt to turn I reach for my metric wrenches first.

MarkII

##### Well-Known Member
The 1/3 inch argument is one of my favorites! It crops up every few years somewhere and I love to here people argue about it.

#### luke strawwalker

##### Well-Known Member
LS: After reading your last post, I really wish I knew more about farm machinery and technology. But for the hydraulic lines, there isn't a hose in an SAE size that is equivalent or even close to the size of the original that could be adapted or made to work?

Don't laugh, but more than once I have had a metric crescent wrench fit over a nut better than the wrench in the fractional size that the nut is supposed to be. But the reverse never seems to occur (fractional-sized wrenches fitting metric nuts). Now, more often than not, when I have a nut to loosen or a bolt to turn I reach for my metric wrenches first.

MarkII

No worries Mark... It's all BS... about like barber shop talk... or presidential speeches :dark: A LOT gets said but NOTHING gets solved... :bangpan:

Anyway, there's always the wrench of last resort-- the BLUE WRENCH!!! https://www.flickr.com/photos/owheeler/428841141/

The "metric crescent wrench" was an old joke... actually I like crescent wrenches on the farm-- we use a BUNCH of them. I can usually use a 14 mm and 9/16 interchangeably, as well as 13 mm and 1/2 inch wrenches, though if it's a SLOPPY (chinese made) wrench 12mm is usually interchangeable with 1/2 inch. Those seem to be the most interchangeable ones... 5/8, 7/16, and most other sizes just seem to be a bit too far off to easily interchange with a metric wrench of close size.

It's a mess, but most stuff seems to have gone to strictly SAE style stuff-- it's just forien stuff from that 'in between' period that's really affected.

Given this old combine, which was actually VERY advanced for it's day, had hydraulically controlled EVERYTHING on it, from the variable speed ground drive, variable speed threshing cylinder, reel height, platform cutterbar height, etc. there are a LOT of hoses on the thing... and given the impossibility of finding metric hydraulic hoses/fittings, I figured I had three choices if I had several hoses fail or a hose fail in such a way it couldn't be respliced-- cut off the old hose ends, strip out the remaining hose with a grinder, and attempt to have them reused on new hoses, or weld the metric hose ends to SAE fittings that a standard SAE hose could attach to, making an "adapter" to allow a new hose to connect up to the weird metric fittings in the variator drives, or attempt to remove the metric fittings from the variator drives or their steel lines and replace them, braze welding on if necessary, new SAE type fittings regular SAE hoses could attach to, or else just junk out an other wise perfectly good machine for lack of a \$50 part-- which is happening more and more with older agricultural equipment...

Later! OL JR

#### MarkII

##### Well-Known Member
The Blue Wrench! Of course! :roll:

Although I usually prefer an even more direct approach.

MarkII

#### MarkII

##### Well-Known Member
LS - I wonder if these people might be able to help you:

https://mdmetric.com/

Also, have you looked into getting the parts from a Canadian supplier?

MarkII

#### Micromeister

##### Micro Craftman/ClusterNut
TRF Supporter
That does explain alot Mark. I thought you were typing just to up your thread count:roll:

#### luke strawwalker

##### Well-Known Member
LS - I wonder if these people might be able to help you:

https://mdmetric.com/

Also, have you looked into getting the parts from a Canadian supplier?

MarkII

Thanks... it's worth a shot...

From what I'm given to understand from folks in the hydraulic business, almost everything forein and domestic has reverted to SAE style hydraulics-- I got the distinct idea that the metric stuff was rather inferior in design and was duplicative so it kinda went away.

YMMV...

Thanks again! OL JR

#### MarkII

##### Well-Known Member
That does explain alot Mark. I thought you were typing just to up your thread count:roll:
Nah, I don't pay any attention to that. It's not important to me.

MarkII

#### Peartree

##### Cyborg Rocketeer
Staff member
Global Mod
In my last job, we used to rebuild many kinds of factory equipment, American made, German, French, you name it. The hardest part of replacing threaded parts was in naming the thread. We had a couple handy books (machinists guides) that helped in identifying them once we measured the thread count and a few dimensions.

Having done that, a few hydraulic places (like Parker Hannifin) would custom make pretty much any hose we wanted, if only we could name the thread that we wanted.

Failing that we could have a local machine shop build an adapter, but again, you had to know the name of the thread.

##### Well-Known Member
Dunno. What's Pi in "English"?

(No Idea why people call it English any more - we've been using metric since the 70's-80's, except for pints of beer and miles for road distance)

I prefer 'Imperial', I must say.
Most English people over about 40 still think in Imperial, even if we use metric every day. Know your enemy. (Just kidding. A bit. Now the EU has stopped trying to compel the destruction of Imperial measure I'm a bit easier about it).
It's still grams and newtons for rocket calculations for me, but heights reached in feet, if you don't mind.

#### Larry Curcio

##### Well-Known Member
Sorry to beat this to death, but it has just occurred to me that there actually *is* a value of Pi in the Imperial System.
It works out to

Pi = .004759989... furlongs per foot

-LarryC

#### MarkII

##### Well-Known Member
Sorry to beat this to death, but it has just occurred to me that there actually *is* a value of Pi in the Imperial System.
It works out to

Pi = .004759989... furlongs per foot

-LarryC
A touch of irrationality can be a good thing...

MarkII

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